Reconstruction of the refractive index profile of planar waveguides using ray tracing analysis

We propose a method for refractive index profiling based on measuring coordinates and angles of laser beams passing across the waveguide layer. Calculations are performed by solving an integral equation using new global optimization methods.

Cross-discipline collaboration and innovation in the design studio : drawing on the Bath model

As information expands and comprehension becomes more complex, so the need increases to develop focused areas of knowledge and skill acquisition. However, as the number of specialty areas increases so the languages that define each separate knowledge base become increasingly remote. Hence, concepts and viewpoints that were once considered part of a whole become detached. This phenomenon is typical of the development of tertiary education, especially within professional oriented courses, where disciplines and sub-disciplines have grown further apart and the ability to communicate has become increasingly fragmented.
One individual and visionary who was well acquainted with the shortcomings of the piecemeal development between the disciplines was Professor Sir Edmond Happold, the leader of the prestigious group known as Structures 3 at Ove Arup and Partners, who were responsible for making happen some of the landmark buildings of their time, including Sydney Opera House and the Pompidou Centre, and the founding professor of the Bath school of Architecture and Civil Engineering in 1975. While still having a profound respect for the knowledge bases of the different professions within the building and construction industry, Professor Happold was also well aware of the extraordinary synergies in design and innovation which could come about when the disciplines of Architecture and Civil Engineering were brought together at the outset of the design process.
This paper discusses the rational behind Professor Happold’s cross-discipline model of education and reflects on the method, execution and pedagogical worth of the joint studio-based projects which formed a core aspect of the third year program at the School of Architecture and Civil Engineering at the Bath University.

Using the Big Mac index for comparing construction costs internationally

This paper explores the use of purchasing power parity (PPP) in the comparison of construction costs between different countries, and whether the development of construction-specific indices will improve reliability.

The approach adopted is to compare the construction cost of a typical five star international hotel per square metre in each of ten major cities using a range of PPP methods and to comment on their variability. In particular, this paper looks at whether an index based on the price of a McDonalds Big Mac3 hamburger is a viable alternative when compared against the mainstream methods. The recent publication of construction-specific indices as part of the Eurostat-OECD joint PPP program is also compared against generic indices and the discrepancy is calculated.

The paper concludes with reflections about which approach is preferable when attempting to assess global construction relativities and what further research is needed.

Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies

A WHO expert consultation addressed the debate about interpretation of recommended body-mass index (BMI) cut-off points for determining overweight and obesity in Asian populations, and considered whether population-specific cut-off points for BMI are necessary. They reviewed scientific evidence that suggests that Asian populations have different associations between BMI, percentage of body fat, and health risks than do European populations. The consultation concluded that the proportion of Asian people with a high risk of type 2 diabetes and cardiovascular disease is substantial at BMIs lower than the existing WHO cut-off point for overweight (25 kg/m2). However, available data do not necessarily indicate a clear BMI cut-off point for all Asians for overweight or obesity. The cut-off point for observed risk varies from 22kg/m2 to 25kg/m2 in different Asian populations; for high risk it varies from 26kg/m2 to 31kg/m2. No attempt was made, therefore, to redefine cut-off points for each population separately. The consultation also agreed that the WHO BMI cut-off points should be retained as international classifications. The consultation identified further potential public health action points (23·0, 27·5, 32·5, and 37·5 kg/m2) along the continuum of BMI, and proposed methods by which countries could make decisions about the definitions of increased risk for their population.

The VISA-A questionnaire: a valid and reliable index of the clinical severity of Achilles tendinoplasty

Background: There is no disease specific, reliable, and valid clinical measure of Achilles tendinopathy. Objective: To develop and test a questionnaire based instrument that would serve as an index of severity of Achilles tendinopathy. Methods: Item generation, item reduction, item scaling, and pretesting were used to develop a questionnaire to assess the severity of Achilles tendinopathy. The final version consisted of eight  questions that measured the domains of pain, function in daily living, and sporting activity. Results range from 0 to 100, where 100 represents the perfect score. Its validity and reliability were then tested in a population of non-surgical patients with Achilles tendinopathy (n = 45), presurgical patients with Achilles tendinopathy (n = 14), and two normal control populations (total n = 87). Results: The VISA-A questionnaire had good test-retest (r = 0.93), intrarater (three tests, r = 0.90), and interrater (r = 0.90) reliability as well as good stability when compared one week apart (r = 0.81). The mean (95% confidence interval) VISA-A score in the non-surgical patients was 64 (59–69), in presurgical patients 44 (28–60), and in control subjects it exceeded 96 (94–99). Thus the VISA-A score was higher in non-surgical than presurgical patients (p = 0.02) and higher in control subjects than in both patient populations (p<0.001). Conclusions: The VISA-A questionnaire is reliable and displayed construct validity when means were compared in patients with a range of severity of Achilles tendinopathy and control subjects. The continuous numerical result of the VISA-A questionnaire has the potential to provide utility in both the clinical setting and research. The test is not designed to be diagnostic. Further studies are needed to determine whether the VISA-A score predicts prognosis.

Dietary patterns throughout adult life are associated with body mass index, waist circumference, blood pressure, and red cell folate

Dietary patterns are important in the prevention of chronic disease; however, there are few studies that include repeat measures of dietary patterns. The objective of this study was to assess the relations between dietary patterns during adult life (at ages 36, 43, and 53 y) and risk factors for chronic disease at age 53 y. Participants of a longitudinal study of health completed a 5-d food diary at 3 occasions during adult life (n = 1265). Factor analysis was used to identify dietary patterns and a pattern score was calculated from the consumption of the food items in each dietary pattern. Means and 95% CI for dietary pattern scores were calculated for each risk factor category using random effects models adjusted for socio-demographic and health-related behaviors. In women, the fruit, vegetables, and dairy pattern was inversely associated with BMI (P < 0.004), waist circumference (P = 0.0007), blood pressure (P = 0.02), and was positively associated with red cell folate (P < 0.03). The ethnic foods and alcohol pattern was also inversely associated with blood pressure (P = 0.008), whereas the meat, potatoes and sweet foods pattern was positively associated with glycated hemoglobin (P = 0.01). In men, a mixed pattern was inversely associated with waist circumference (P = 0.02) and blood pressure (P = 0.01), whereas there were no significant associations with the ethnic foods and alcohol pattern. Specific dietary patterns throughout adult life were associated with chronic disease risk factors.

Effect of relaxation on pressure sensitivity index in a Zr-based metallic glass

Shear-banding features of as-cast and annealed Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 bulk metallic glass were investigated through Rockwell indentation tests. Isothermal annealing of the as-cast samples was conducted at temperatures below its glass transition temperature, Tg. The exothermal enthalpy during continuous heating below Tg decreases with increasing annealing temperature, indicating the gradual reduction of free-volume upon annealing. The observation on the morphology of shear-banding pattern around the indents implies a reduced shear bands activity in the annealed samples. The included angles (2θ) between two families of shear bands emanating from the edge of Rockwell indent decrease from 88° for the as-cast sample to 79° for the sample annealed at 633 K for 1 h, indicating a pressure sensitive plasticity. By Mohr–Coulomb criterion, the pressure sensitive index can be obtained on the basis of the measured 2θ, which increases with increasing annealing temperature, indicating an increase of “atomistic friction” due to the reduction of the free volume upon annealing.

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

Background
While much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).
Methods
This prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5–10 years at baseline and 8–13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was ≤14 hrs/wk.
Results
Electronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.

Conclusion
Electronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.

Stability of body mass index in Australian children: a prospective cohort study across the middle childhood years

Objective: To investigate the prevalence and incidence of overweight and obesity, the frequency of overweight resolution and the influence of parental adiposity during middle childhood.

Design: As part of a prospective cohort study, height and weight were measured in 1997 and 2000/2001. Children were classified as non-overweight, overweight or obese based on standard international definitions. Body mass index (BMI) was transformed into age- and gender-specific Z-scores employing the LMS method and 2000 growth chart data of the Centers for Disease Control and Prevention. Parents self-reported height and weight, and were classified as underweight, healthy weight, overweight or obese based on World Health Organization definitions.

Setting: Primary schools in Victoria, Australia.

Subjects: In total, 1438 children aged 5–10 years at baseline.

Results: The prevalence of overweight and obesity increased between baseline (15.0 and 4.3%, respectively) and follow-up (19.7 and 4.8%, respectively; P < 0.001 for increase in overweight and obesity combined). There were 140 incident cases of overweight (9.7% of the cohort) and 24 of obesity (1.7% of the cohort); only 3.8% of the cohort (19.8% of overweight/obese children) resolved to a healthy weight. The stability of child adiposity as measured by BMI category (84.8% remained in the same category) and BMI Z-score (r = 0.84; mean change = −0.05) was extremely high. Mean change in BMI Z-score decreased with age (linear trend β = 0.03, 95% confidence interval 0.01–0.05). The influence of parental adiposity largely disappeared when children's baseline BMI was adjusted for.

Conclusions: During middle childhood, the incidence of overweight/obesity exceeds the proportion of children resolving to non-overweight. However, for most children adiposity remains stable, and stability appears to increase with age. Prevention strategies targeting children in early childhood are required.

Change in women's body mass index and waist circumference, 1997 to 2002: the Nepean study

Objective: To investigate character istics associated with body mass index (BMI) and waist circumference stability over a five-year period in women with school-age children.

Methods: Women with 7–8 year-old children from western Sydney, Australia, had anthropometric measures taken in 1996/97 (n====436) and five years later (n=327). Socio-demographic characteristics examined at baseline included age, socioeconomic status, smoking, and number of children.

Results: Over five years, less than half of the women maintained a stable BMI (38.8%) or waist circumference (31.5%), with the majority gaining in both indicators of adiposity. BMI and socio-demographic characteristics were not predictive of BMI or waist circumference stability or decrease.

Conclusions and Implications: Total and abdominal adiposity increased in these Australian women who have children. The results support the need to develop effective weight gain prevention initiatives.

An investigation into the cross-cultural equivalence of the personal wellbeing index

The Personal Wellbeing Index (PWI) is being developed for the cross-cultural measurement of subjective wellbeing (SWB). This paper reports the findings of its utility with the Hong Kong Chinese and Australian populations. An item on affect, ‘satisfaction with own happiness’ was also investigated to determine whether it should be added to the index. Three-hundred and sixty participants (180 per country), with equal representation from groups aged 18–35, 35–64 and 65 years and above, were recruited from each country. The PWI demonstrated good psychometric performance in terms of its reliability, validity and sensitivity, which are comparable in both countries. The item ‘satisfaction with own happiness’ was found to contribute significantly to the scale’s psychometric performance in Australia but not in Hong Kong. Cultural differences in the perception of the concepts ‘satisfaction’ and ‘happiness’ were suggested as an explanation for this finding. The PWI data are also consistent with homeostasis theory, which proposes that each person’s SWB level is maintained within a limited positive range. For the Australian population, their mean SWB level fell within the established Western range of 70–80, on a scale from 0 to 100. The Hong Kong population, however, fell below this range. Cultural response bias was identified as a plausible explanation for the differences between the Hong Kong and Australian samples.

Family average income and body mass index above the healthy weight range among urban and rural resicents in regional Mainland China

Objective: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. Design: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. Setting: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. Subjects: In total, 29 340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. Results: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. Conclusions: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.